Furnace bottom



Aug. 15, 1939. T. E. MURRAY. JR

FURNACE BOTTOM- Filed Jan.

INVENTOR ATTORNEYS Patented Aug. 15, 1939 UNITED STATES PATENT OFFICE FURNACE BOTTOM Thomas E. Murray, Jr., Brooklyn, N. Y.

Application January 19, 1935, Serial No. 2,606

4 Claims. (01. 122-235) The invention aims to provide a floor for furtrated. This relation is obtained and maximum naces of boilers or the like which is economical surface exposure secured, by making the projecand'durable and has other advantages referred tions of greater dimensions transversely than to in detail hereinafter. lengthwise of the tube. Fig. 1 is a longitudinal section of a boiler. The front wall illustrated is the invention of 5 Fig. 2 is a plan of a part of the floor. Fig. 3 is John H. Lawrence and is claimed in his co -pend a side elevation of one of the tubes. ing application Serial No. 4,051, filed January 30,

Referring to Fig. 1, the boiler l I may comprise 1935. any usual or suitable arrangement of water tubes Various other modifications may be a y located above a furnace combustion chamber [2. those skilled in the art without departing from 10 Pulverized fuel burners l3 project the flame downthe invention as defined in the following claims. ward whence it turns upward, filling the chamber What I claim is: and passing through the overhead tubes. The 1. A furnace for boilers or the like for burning front wall comprises vertical tubes M with flanges fuel in suspension having a bottom comprising between them and spaces through which air is parallel tubes spaced apart, each having in heat- 15 admitted for combustion. V The rear wall comconducting engagement with it a series of spaced prises similar tubes I5 with an outer covering short metal projections extending toward the of insulating material. The floor of the chamber next tube, the projections being in the form of comprises a number of tubes l6 inclined downthin plates with their narrow edges approximately 7 wardly toward the front and connected by headori onta and heir W de ce approximately 20 ers I1 and I8 to the tubes of the front and back vertical.

walls and thus into the circulation of the boiler. 2. A furnace for boilers or the like for bur The water circulating through the floor tubes is e in Suspension having a bottom Comprising heated and at the same time keeps the floor comparallel tubes spac p each having in heatparatively cool. Ashes and slag deposited thereconducting enga eme t W h t a er o p d 5 on are cooled and are sufiiciently granular to short metal projections eXtending wa e pass through the spaces between the tubes. next tube, the projections having their vertical The tubes are spaced apart as in Fig. 2 and dimension greater than their dimension lengthnave projections l9 extending outward therefrom, Wise of the tubes.

the projections from two adjacent tubes extend- A furnace for boilers or e like for burning 3o ing approximately across the space between them. e in Suspension having a bottom Comprising The projections on the tubes provide an extension parallel tubes pa p a having n heatof the area exposed to the hot ashes and slag n uct n en e n w h i a series of p d and increase the rapidity of the heat exchange short metal projections extending toward the next with the water within. tube, the spaces being sufiicient to pass sub- 35 Preferably the projections are comparatively stantially all the ashes to the floor below and the small at their ends and are welded at such ends d me s o s of t e p oje s t wise o t e with resistance butt welds to the tubes. A plutu s bein l h n id spaces n being so rality of such projections closely spaced is adslight as to o e no Substantial sup-port for an vantageous. It has-been found that where flanges accumulation of ashes. 40 or projections are united by comparatively long 4. A furnace for boilers or the like for burnwelds, say more than twelve inches, the welding 8" e n Suspe having a b tt S een operation sets up strains in. the tubes upon concomprising substantially parallel tubes spaced traction which may cause them to fail in use and p at 1east m of said tubes h v n heatalso sets up strains in the projections which deconducting ga ement With them a series of creases their resistance to oxidation, particularly spaced short metal projections extending toward at high temperatures, and thus reduces the width the n x tube, the spaces being sufficient p to which they may be extended beyond the tubes substantially all the ashes to the floor below and without burning out in practice. the dimensions of the projections lengthwise of The spaces between the projections [9 are sufthe tubes being less than said spaces and being ficient to pass ashes to the pit below. The space So Slight s to offer Substantial pp for from one projection Hi to the next is at least an accumulation of ashes. equal to the dimension of the projection length- THOMAS E. MURRAY, JR. wise of the tube, and may be greater as illus- 

